Detection of the Cosmic Far-Infrared Background in the AKARI Deep Field South - Astrophysics > Cosmology and Nongalactic AstrophysicsReport as inadecuate




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Abstract: We report the detection and measurement of the absolute brightness andspatial fluctuations of the cosmic infrared background CIB with the AKARIsatellite. We have carried out observations at 65, 90, 140 and 160 um as acosmological survey in AKARI Deep Field South ADF-S, which is one of thelowest cirrus regions with contiguous area on the sky. After removing brightgalaxies and subtracting zodiacal and Galactic foregrounds from the measuredsky brightness, we have successfully measured the CIB brightness and itsfluctuations across a wide range of angular scales from arcminutes to degrees.The measured CIB brightness is consistent with previous results reported fromCOBE data but significantly higher than the lower limits at 70 and 160 umobtained with the Spitzer satellite from the stacking analysis of 24-umselected sources. The discrepancy with the Spitzer result is possibly due to anew galaxy population at high redshift obscured by hot dust. From powerspectrum analysis at 90 um, three components are identified: shot noise due toindividual galaxies; Galactic cirrus emission dominating at the largest angularscales of a few degrees; and an additional component at an intermediate angularscale of 10-30 arcminutes, possibly due to galaxy clustering. The spectralshape of the clustering component at 90 um is very similar to that at longerwavelengths as observed by Spitzer and BLAST. Moreover, the color of thefluctuations indicates that the clustering component is as red asUltra-luminous infrared galaxies ULIRGs at high redshift, These galaxies arenot likely to be the majority of the CIB emission at 90 um, but responsible forthe clustering component. Our results provide new constraints on the evolutionand clustering properties of distant infrared galaxies.



Author: S. Matsuura, M. Shirahata, M. Kawada, T. T. Takeuchi, D. Burgarella, D. L. Clements, W.-S. Jeong, H. Hanami, S. A. Khan, H. Matsu

Source: https://arxiv.org/







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